1. Field of the Invention
The invention relates to the chemical synthesis of conjugated diene hydrocarbons and more particularly relates to the synthesis of a (Z,Z) conjugated diene aldehyde.
2. Brief Description of the Prior Art
P. E. Sonnet and R. R. Heath J. Chem. Ecol., 6 (1), 221-28 (1980) describe a straightforward approach to obtaining the conjugated diene system through borane reduction of the appropriate diyne obtained from Chodkiewicz-Cadiot coupling of the appropriate acetylenes. This process suffers, however, from two weaknesses; it utilizes chromium oxidation to generate the aldehyde and two equivalents of expensive dicyclohexyl borane to reduce the diyne to the diene.
Fujimoto et al. in Chem. Pharm. Bull. Japan, 24, 365 (1976) have described the chlorination of unsaturated alcohols using methanesulfonyl chloride as the chlorinating agent in a single step procedure.
The synthesis of internal conjugated (Z)-enynes has been reported in Tetrahedron Letters, No. 7, 633-34 (1979) by G. Cassani, et al.
The stereospecific reduction of a (Z)-ene-yne has been described by a number of prior artisans; see for example E. Truscheit & K. Eiter, Annalen, 1961, 658-65; A. Butenandt, et al., Ibid., 1962, 658, 39; and E. Negishi, et al., J.C.S. Chem. Comm., 1973, 874.